1. Field of the Invention
The present invention relates to a method for manufacturing a liquid jet recording head used for a liquid jet recording apparatus or the like. More particularly, the invention relates to a method for manufacturing a liquid jet recording head which is structured by combining an element substrate having an array of discharge energy generating elements with a ceiling plate having arrays of discharge ports and flow path grooves.
2. Related Background Art
A liquid jet recording head used for a liquid jet recording apparatus or the like comprises an element substrate having a plurality of discharge energy generating elements (electrothermal converting elements, for example) formed at given intervals, and a ceiling plate having a plurality of discharge ports formed for discharging ink or some other liquid, as well as a plurality of flow path grooves conductively connected with each of the discharge ports. The element substrate and the ceiling plate are combined and bonded in a state where the discharge energy generating elements, the discharge ports, and the flow path grooves are positioned exactly. Then, the head is structured to apply discharge energy to liquid in each of the flow path grooves by means of discharge energy generating elements, thus discharging liquid from the discharge ports as droplets to record prints on a recording medium.
As shown in FIGS. 8A and 8B, a liquid jet recording head of the kind comprises an element substrate (heater board) 51 having cut faces 51a and 51a on both ends thereof, which is provided with a plurality of discharge energy generating elements (electrothermal transducing devices or heaters) 52 formed and arranged by means of micro-precision etching technologies and techniques on the element substrate at given intervals; and a ceiling plate 53 having a plurality of discharge ports 54 formed in a given precision by use of laser processing or the like, as well as a plurality of flow path grooves 55 conductively connected with each of the discharge ports, and also, a common liquid chamber 56 and a liquid supply inlet port 57. The element substrate 51 and the ceiling plate 53 are fixed by the application of bonding agent or by use of a spring or the like in a state that the respective discharge energy generating elements 52 on the element substrate 51, and the discharge ports 54 and the flow path grooves 55 on the ceiling plate 53 are positioned correspondingly, thus forming a liquid jet recording head.
Now, however, when an element substrate of the kind is combined with the ceiling plate, the accuracy of micron order is required for positioning the discharge energy generating elements on the element substrate, and the discharge ports and flow path grooves of the ceiling plate. In this respect, there are disclosed in Japanese Patent Application Laid-Open No. 4-171126, Japanese Patent Application Laid-Open No. 4-171130, and Japanese Patent Application Laid-Open No. 4-171163, among some others, methods for manufacturing an liquid jet recording head wherein positioning is made precisely adjustable when the element substrate and ceiling plate are combined. These methods for manufacturing a liquid jet recording head are such that at first, the positions of the discharge energy generating elements (heaters), which should be formed on an element substrate (heater board), are measured by means of image processing or the like, and then, a ceiling plate is allowed to shift onto the element substrate, and that the ceiling plate is subsequently moved relatively with respect to the element substrate, while measuring the positions of the discharge ports or flow path grooves formed on the ceiling plate by means of image processing or the like, so that the positions of discharge ports or the flow path grooves agree with those of the discharge energy generating elements on the element substrate. In this manner, the element substrate and the ceiling plate are arranged, and when the discharge energy generating elements, discharge ports, and flow path grooves are positioned exactly in agreement with each other, the substrate and plate are bonded and fixed by the application of a bonding agent or by use of a spring or the like.
Also, between the discharge energy generating elements (heaters) formed on the element substrate, there are arranged recessed portions, respectively, which engage with the flow path walls that constitute the flow path grooves of the ceiling plate. Then, the end face of the element substrate is allowed to abut upon the reference surface which is provided for the ceiling plate in advance. After that, the ceiling plate is caused to shift by the application of vibrations. In this manner, the flow path walls of the ceiling plate engages with the recessed portions arranged on the element substrate. This method, which is disclosed in the specification of Japanese Patent Application Laid-Open No. 7-89073 filed by the applicant hereof, makes it possible to position the element substrate and the ceiling plate quickly. Further, the applicant hereof has proposed a method wherein an abutment reference is arranged in advance for the ceiling plate for use of its bonding with the element substrate, and then, after the ceiling plate has shifted onto the element substrate, the end face of the element substrate is caused to abut upon the abutment reference of the ceiling plate, hence making it possible to execute the positioning of the element substrate and ceiling plate quickly with ease.
However, each of the conventional methods for manufacturing a liquid jet recording head that have been described above still has problems yet to be solved as given below.
In other words, as to the method wherein the positions of the discharge energy generating elements on the element substrate are measured by means of image processing or the like, and the element substrate and the ceiling plate are positioned by moving them relatively, while measuring the positions of the discharge ports of the ceiling plate by means of the image processing or the like, an operation is needed to move the ceiling plate after the positions of the discharge energy generating elements on the element substrate have been measured. Further, it is required to repeatedly measure the positions of the discharge ports of the ceiling plate, and move it several times until the positions of the discharge energy generating elements on the element substrate and those of the discharge ports of the ceiling plate agree with each other. As a result, a problem is encountered that the tact time should increase. Also, the positioning is carried out while the measurements are made by means of a non-contact type, such as image processing method. Therefore, it is inevitable that the structure of a system becomes complicated, resulting in higher costs, and that the time required for making adjustment for each part becomes different due to the difference in the adjustments necessitated to be made by the varied precisions in which the element substrates are cut. This complicated structure of the system may hinder balancing the line tacts, and further, may make it difficult to carry out the required positioning in a shorter period of time.
Also, for the method wherein the element substrate and the ceiling plate are positioned by the provision of the positioning recesses between the plural discharge energy generating elements (heaters) on the element substrate or the method wherein the element substrate and the ceiling plate are positioned by allowing the end face of the element substrate to abut upon the abutment reference arranged for the ceiling plate, it is difficult to form the positioning recesses between the discharge energy generating elements if the devices are arranged in high density on an element substrate which is adopted for use of a highly densified recording head, such as 600 dpi or more, although this method makes it possible to carry out the positioning quickly with ease. Also, for the method wherein the end face of the element substrate is allowed to abut upon the abutment reference arranged for the ceiling plate, the positional deviation may take place between the discharge energy generating elements on the element substrate and the discharge ports or the flow path grooves of the ceiling plate depending on the precisions in which the element substrates are cut. As a result, there is a problem that this method is not adoptable for the assembling of highly densified recording heads, such as 600 dpi or more.
Therefore, the present invention is designed in consideration of the problems yet to be solved for the conventional art described above. It is an object of the invention to provide a method for manufacturing a liquid jet recording head capable of carrying out positioning in a higher precision with a shorter tact time at lower costs for the manufacture of a highly densified liquid jet head having a higher precision and reliability.
In order to achieve the objective described above, the method of the present invention for manufacturing a liquid jet recording head, which is provided with an element substrate having an array of discharge energy generating elements, and a ceiling plate having discharge ports and flow path grooves arranged in lines, the liquid jet head being assembled by the element substrate and the ceiling plate being fixed by the application of bonding agent or by use of spring or the like after positioning the discharge energy generating elements on the element substrate and the flow path grooves on the ceiling plate to present a specific positional relationship, comprises the steps of measuring the distance from a specific discharge energy generating element on the element substrate to the end face of the element substrate in the arrangement direction of discharge energy generating elements, and calculating the difference between the measured distance and the distance set in advance for the ceiling plate; of overlaying the element substrate and the ceiling plate, and enabling the abutment reference of the ceiling plate in the arrangement direction of the flow path grooves to abut upon the end face of the element substrate; and of moving relatively for retraction the end face of the element substrate in abutment with the abutment reference of the ceiling plate in the direction in which the end face parts from the abutment reference in accordance with the result of calculation obtained in the calculating step, hence the element substrate and the ceiling plate being positioned and assembled.
Also, the method of the present invention for manufacturing a liquid jet recording head, which is provided with an element substrate having an array of discharge energy generating elements, and a ceiling plate having discharge ports and flow path grooves arranged in lines, the liquid jet head being assembled by the element substrate and the ceiling plate being fixed by the application of bonding agent or by use of spring or the like after positioning the discharge energy generating elements on the element substrate and the flow path grooves on the ceiling plate to present a specific positional relationship, comprises the steps of measuring the distance from a specific discharge energy generating element on the element substrate to the end face of the element substrate in the arrangement direction of discharge energy generating elements, and calculating the difference between the measured distance and the distance set in advance for the ceiling plate; of overlaying the element substrate and the ceiling plate, and enabling the abutment reference of the ceiling plate in the arrangement direction of the flow path grooves to abut upon the end face of the element substrate; and of moving relatively for retraction the end face of the element substrate in abutment with the abutment reference of the ceiling plate in the direction in which the end face parts from the abutment reference in accordance with the result of calculation obtained in the calculating step and the correction value calculated in consideration of the compression resulting from the abutment, the positional deviation, and some others, hence the element substrate and the ceiling plate being positioned and assembled.
Now, for the method of the present invention for manufacturing a liquid jet recording head, it is preferable that the distance set in advance for the ceiling plate is the distance from a specific flow path groove or discharge port corresponding to the specific discharge energy generating element on the element substrate to the abutment reference in the arrangement direction of the flow path grooves.
Also, it is preferable for the method of the present invention for manufacturing a liquid jet recording head to calculate a correction value in consideration of the compression resulting from the abutment, the positional deviation, and some others from the distribution of measured values of the element substrates and ceiling plates after positioning and fixing the element substrates and ceiling plates, and feed back such correction value for determining the amount of retraction.
Further, it is preferable for the method of the present invention for manufacturing a liquid jet recording head that the correction value calculated in consideration of the compression resulting from the abutment, the positional deviation, and some others is obtained in accordance with the result of calculation on the basis of a first distance from a specific discharge energy generating element on the element substrate to the end face of the element substrate and the distance set in advance for the ceiling plate by overlaying the element substrate and the ceiling plate, and subsequently, enabling the end face of the element substrate and the abutment reference of the ceiling plate in the arrangement direction of flow path grooves to abut upon each other, and then, after the ceiling plate and the element substrate are positioned and fixed by moving relatively the end face of the element substrate and the abutment reference of the ceiling plate in the direction in which the end face and reference part from each other, the distance from the end face of the element substrate to a specific flow path groove is measured to calculate the positional precision between the measured value and the first distance, and a correction value is worked out from the distribution of the positional precisions, and fed back to correct the result of calculation for determining the restoring amount of abutment.
Also, it may be possible to structure the method of the present invention for manufacturing a liquid jet recording head so that the position of the push jig for compressing the ceiling plate or the element substrate is measured and stored when the end face of the element substrate abuts upon the abutment reference of the ceiling plate; the position of the push jig is continuously measured when the end face of the element substrate is moved relatively in the direction in which the face parts from the abutment reference of the ceiling plate, and the retraction movement is suspended when the difference between the measured position of the push jig and the stored measurement becomes identical to a specific amount of retraction or to a value close thereto. Also, it may be possible to arrange the structure of the method of the present invention so that a load sensor is provided for the retraction jig for performing retraction when the end face of the element substrate is moved relatively in the direction in which the face parts from the abutment reference of the ceiling plate after the face abuts upon the abutment reference; and the load sensor is continuously read to perform retraction by restoring the retraction jig in a distance substantially equal to a specific amount of retraction from the point indicating the change of load to present the increase more than the specific amount.
Further, it may be possible to arrange the structure of the method of the present invention for manufacturing a liquid jet recording head so that the ceiling plate is fixed, the element substrate moves onto the ceiling plate, and the element substrate abuts upon the abutment reference of the ceiling plate, and then, retraction is performed or that the element substrate is fixed, the ceiling plate moves onto the element substrate, and the abutment reference of the ceiling plate abuts upon the element substrate, and then, retraction is performed.
Also, it is preference for the method of the present invention for manufacturing a liquid jet recording head that the discharge energy generating elements are electrothermal transducing devices.
In accordance with the present invention, the method for manufacturing a liquid jet recording head makes it possible to combine an element substrate and a ceiling plate so that the discharge energy generating elements on the element substrate and the flow path grooves on the ceiling plate present a specific positional relationship, thus fixing them by the application of bonding agent or the like to assemble a liquid jet recording head. In this method, the distance is measured from a specific discharge energy generating element on the element substrate to the end face of the element substrate in the arrangement direction of discharge energy generating elements, and calculating the difference between the measured distance and the distance set in advance for the ceiling plate; the element substrate and the ceiling plate are overlaid to enable the abutment reference of the ceiling plate in the arrangement direction of the flow path grooves to abut upon the end face of the element substrate; and the end face of the element substrate in abutment with the abutment reference of the ceiling plate is moved relatively for retraction in the direction in which the end face parts from the abutment reference in accordance with the result of calculation obtained in the calculating. Then, after the abutment reference of the ceiling plate abuts upon the end face of the element substrate by means of the push jig, the element substrate is moved for positioning by means of the retraction jig from that position in the direction in which it parts from the abutment reference of the ceiling plate in an amount equal to the difference between the distance from the abutment reference of the ceiling plate to a specific discharge port or flow path groove, and the distance from the end face of the element substrate to a specific discharge energy device. In this manner, positioning becomes possible at lower costs in a shorter tact time and in a higher precision, hence manufacturing a highly reliable and highly densified liquid jet recording head.
Also, in accordance with the method of the present invention for manufacturing a liquid jet recording head, it is possible to measure the deviations of positional precisions in the state after positioning is actually made by the retraction on the basis of the result of calculation in the calculation step when moving the end face of the element substrate that abuts upon the abutment reference of the ceiling plate in the direction in which it parts from the abutment reference. Then a correction value is worked out for the amount of retraction from the distributional condition of such amounts of deviation. This correction value is fed back for determining the corrected amount of restoration. In accordance with the restoring amount thus corrected, positioning is performed in a higher precision at lower costs and in a shorter tact time, hence making it possible to manufacture a highly reliable and highly densified liquid jet recording head.